Interim Chief Pat Pidgen is brought over to temporarily fill in for Boden, who is left to tend to his personal affairs. When tension is sparked as the result of his derisive leadership, the absence of Chief Boden becomes all too apparent. Meanwhile, Lieutenant Severide must deal with a most unwelcome addition to his squad, Brett gets closer to a girl she previously rescued and Casey starts seeing a new woman, Beth, but interesting complications quickly unfold.